The diagnosis and treatment of patients with cancerous tumors, pre-malignant conditions, and other disorders has long been an area of intense investigation. Non-invasive methods for examining tissue include palpation, thermography, PET, SPECT, Nuclear imaging, X-ray, MRI, CT, and ultrasound imaging. When the physician suspects that tissue may contain cancerous cells, a biopsy may be done either in an open procedure or in a percutaneous procedure. For an open procedure, a scalpel is used by the surgeon to create a large incision in the tissue in order to provide direct viewing and access to the tissue mass of interest. Removal of the entire mass (excisional biopsy) or a part of the mass (incisional biopsy) is performed. For a percutaneous biopsy, a needle-like instrument is inserted through a very small incision to access the tissue mass of interest and to obtain a tissue sample for later examination and analysis.
The advantages of the percutaneous method as compared to the open method are significant: less recovery time for the patient, less pain, less surgical time, lower cost, less risk of injury to adjacent bodily tissues such as nerves, and less disfigurement of the patient's anatomy.
Generally there are two ways to percutaneously obtain a portion of tissue from within the body: aspiration and core sampling. Aspiration of the tissue through a fine needle requires the tissue to be fragmented into pieces small enough to be withdrawn in a fluid medium. This method is less intrusive than other known sampling techniques, but one may only examine cells in the liquid (cytology) and not the cells and the structure (pathology). In core sampling, a core or fragment of tissue is obtained for histologic examination and/or genetic tests, which may be done via a frozen or paraffin section. The type of biopsy used depends mainly on various factors present in the patient, and no single procedure is ideal for all cases. However, core biopsies seem to be more widely used by physicians.
The following patent documents are incorporated herein by reference for the purpose of illustrating biopsy devices and methods: U.S. Pat. No. 5,526,822 issued Jun. 18, 1996; U.S. Pat. No. 5,895,401 issued Apr. 20, 1999; U.S. Pat. No. 6,086,544 issued Jul. 11, 2000; U.S. Pat. No. 6,620,111 issued Sep. 16, 2003; U.S. Pat. No. 6,626,849 issued Sep. 30, 2003; U.S. Pat. No. 6,638,235 issued Oct. 28, 2003; US Patent Application 2003/0109803 published Jun. 12, 2003; US Patent Application 2003/0199753 published Oct. 23, 2003; US Patent Application 2003/0199754 published Oct. 23, 2003; US Patent Application 2003/0199785 published Oct. 23, 2003; and U.S. Ser. No. 08/825,899 filed on Apr. 2, 1997.
It is known in the art to use a double lumen biopsy needle incorporating vacuum suction to obtain a tissue sample. With devices of this type, the needle is inserted into a small incision in a patient and is advanced through tissue until the needle is adjacent the tissue of interest. At that point, a vacuum source may be activated, providing suction inside one of the two lumens. The suction is communicated to the second lumen via a passage between the two lumens. The second lumen may contain an aperture through which suspicious tissue may be drawn when the vacuum source is activated. Once tissue is drawn into the aperture, the surgeon may advance a cutter through the second lumen in order to excise a sample from the tissue of interest.
While biopsy needles of the type described above are useful in obtaining tissue samples, the processes known in the art for manufacturing these needles are often expensive and labor-intensive due to the number of components and steps involved. For instance, certain biopsy needles provide a double lumen structure formed of two separate rigid structures, thus requiring a reliable method of attaching the two structures, such as a weld or adhesive, along the entire length of the lumens. Similarly, many biopsy needles include a sharpened feature on the leading end of the needle that cuts through tissue as the needle is advanced into the body. These sharpened tips often have small components and/or features that require significant time and expense to make and attach to the needle. Further, biopsy needles often include a mounting component that allows the needle to be attached to a handle or other platform. Often, these mounting components are manufactured separately from the body of the needle, and must be joined together after formation, such as by gluing, a process that is heavily reliant on the skill and concentration of a human worker. Even if a more reliable method of attaching the mounting component to the needle is used, such as induction heating or heat staking, such methods still involve the added expense necessitated by the extra assembly equipment as well as the steps of manufacturing the mounting component and attaching it to the needle.
Accordingly, while double lumen biopsy needles are known in the art, there exists a significant need for a process of manufacturing a biopsy needle that reduces the number of components that must be separately manufactured, as well as the time and labor that must be expended in manufacturing and assembling the components of the biopsy needle, while still maintaining the necessary strength and rigidity for safe and satisfactory performance during surgery.